When it comes to the medical field, practice very definitely makes perfect. But when it comes to surgery time, doctors can't have time to practice -- they need to get it right every single time, no matter the technique or the patient. For this reason, some medical schools will have their students practice on pigs -- dead or anesthetized, whole or in parts -- in order to make sure they've got the method down pat. If you're curious about exactly what procedures have been practiced on a pig long before you're on the table, then here's what you need to know.

Surgery

Medical students all across the country learn via simulators how to handle the stress and the procedures of the operating room. But though it's going out of fashion, some schools (notably Johns Hopkins) still use pigs to help their students learn to perform surgery.

While detractors argue that this is simply animal cruelty, its supporters remind them that the pigs are anesthetized before the procedures, and that getting hands on, textured experience with surgery (which no simulation can offer) can give a student a bit of help if he or she is wondering whether they could handle actually operating on a person. If they're fine with simulations but get sick at actually stitching tissue, they can switch careers before spending a lot of time, money, and possibly endangering patients' lives.

Laser Eye Techniques

Pig's skin, muscle, and tissue are very similar to their human counterparts -- and it turns out that their eyes are as well. Laser eye surgery,also known as LASIK surgery,  while near-miraculous in its effect on everyday life, is still dangerous and can be tricky to perform if the doctor has rarely performed one before. Pigs' eyes, leftover after the mature animals themselves are butchered for meat, can be purchased by medical trainers and institutions for their students to practice the fine-motor skills necessary to complete a successful laser eye procedure.

Suturing

Sutures -- known to the layman as stitches -- are the bread and butter of the medical world, and are used in hundreds of procedures, from sewing up a simple gash to layered sutures after a Caesarian section. Pigs' hooves (removed from the body) are often used to help medical students learn perfect suturing technique. This experience helps the soon-to-be doctors keep a clear head and a steady hand when it comes to stitching up human patients, allowing them to perform surgery with the confidence that can only come from repetition.